Electrical system for engines



c. F. KETTERING AND w. A. CHRYST. ELECTRICAL SYSTEM FOR ENGINES- APPLICATION FILED FEB- 17, F916- 1,401,837, Patented Dec. 27, 1921..

UNITED PATENT OFFICE.

CHARLES F. KETTERING AND WILLIAM A.

THE DAYTON ENGINEERING LABORATORIES COMPANY, A CORPORATION OF OHIQ ELECTRICAL SYSTEM FOR ENGINES.

Specification of Letters Patent.

Original application filed July 16, 1914, Serial No. 851359. Divided and this a Serial No. 78,894.

To all whom it may concern:

Be it known that we, CHARLES F. KETTER- ING and lViLLmM A. Ci-inYsT, citizens of the United States of America, residing at Dayton county of lllo'iitgomery, and State of Dhio, have invented certain new and useful Improvements in Electrical Systems for Engines, of which the following is a full, clear, and exact description.

The present invention relates to an improvement in electrical systems and associated devices. I

The present application is a division of our copending application, Serial No. 851; 259, filed July 16, 1914.

One of the objects of the present invention is to combine a. rheostat with an electrical system, in such a manner that said rheostat may beautomatically shifted from time to time, relative to a cooperating contact, so as to present different surfaces to said contact.

This intermittent shifting of the rhcost-at tends to prevent burning and pitting of the resistance element thereof, and also to prevent undue wear on any particular portion of said rheostat. 7

Further objects and advantages of the present invention will appear from the. following description,reference being had to the accompanying" drawings, wherein one preferred form of the present invention is clearly illustrated.

In the drawings:

Figure 1 is a diagrammatic view of the electrical circuits connections and devices which may be employed in the present in vcntioii.

Fig. 2 is a viewpartly in elevation and partly in section of a casing. wherein. the rheostat and certain associated mechanism is mounted.

Fig. 3 is a detail showingthe rhcostat or resistance unit removed from the casino".

Referring to the drawing. and more particularly to Fig. 1, the numeral 20 desig nates an electric machine. capable of. operation as a generator, to supply current to the storage battery 21., or to work circuits and their associated devices.

This generator in the present instance is Patented Dec. 27, 1921 pplication filed February shown as having; a shunt field winding 22' accordance with the speed of the engine.

The electrical system, including the resistance element. and its combination with certain other features of said system, have been clearly described, illustrated and claimed in our Patent No. 1,272,055, issued Julvv 9, 1918, and it is therefore deemed. unnecessary to give a further description of this system in the,present application.

As has been described above, the amount.

of resistance which is to be out into the field circuit is controlled by the contact element 25, W'lllCll lll turn 15 actuated in accordance with the speed of the engine. This contact.

element is so arranged that as the speed of the engine increases or decreases, said element will be moved relative to the resistance unit 24. in such a manner that a part of said contact element will wipe over the resistance material 26 included in said unit.

Now, if the same part of this resistance unit 24 were continuously engaged bythe contact clement, it would tend to cause an undue amount of wear on the particular portion of the resistance with which the contactengragcs. There would also be a tendency for the adjacent coils of the resistance unit to pit and burn and thereby render the system inefficient if not entirely inoperative. In Fig. 2 a casing 27 is illustrated, which may form the front end ofthe generator 20. This casing is provided with compartments, in one of which is positioned the gear wheel 28, which forms a direct driving means from the engine to the movable elements hereinafter described. This gear wheel is provided withspiral teeth 29 which mesh with CHRYST, OF DAYTON, OHIO, ASSIGNOM T0 a pinion 30, which in turn is mounted upon mp /a The main shaft 32 is preferably of hollow construction and is adapted to receive one end of the cam-carrying element 33. Intermediate the ends of the shaft 32 there is provided a centrifugal device 34, which in-- cludes an element-35, pivoted to the shaft 32 at the; point 36, and connected to a slidable collar 37 by means of the arms 38, one end of which aresecured to the collar 37, while the opposite finds are secured tq said centrifugal element 35.

tioned co-pendin application,

As will appear from the heretofore menthis centrifugal element ten 3 to automatically control the advance and retard of the time of occurrence-of the sparking impulses in the ignitends to control the amount of resistance which is cut into and out of the field circuit, in accordance with the speed of the engine. The manner in which this centrifugal element controls the resistance of the field circuit will now be described.

1 The collar 37, to which the centrifugal element is connected, is. provided with a pcripheral groove 38, wherein a bearing mem- 'ber 39, shown in dottsed lines injFig. 2 is positioned. This beai'lngelenlbnt is carried by an arm 49, one end of which is. pivoted as at 41', to one of the walls of'the end housing'27. The opposite end of said arm is formed into a. contact wiper, 25, clearly shown in Fig. 2, and lies in such position that it will pass over the resistance spool or'reel' 24, atsuch times as the said arm is moved by the operation of'the centrifugal member 34.

The resistance reel or spool 24 is formed of suitable insulating material and is preferably grooved,"as is shown in big. 3, to receive a resistance wire 26, the opposite terminals of which are connected tolthe terminal posts '42 and 43 respectively, in any suitable manner,see Figs. 1 and 2.

Now, in order to prevent undue wear of the resistance wire or material, mechanism is provided, whereby the said spool or'reel will be actuated to present, intermittently,

different surfaces of said resistance wire or material for thecontact wiper to pass over,

thus substantially distributing the wear over the entire surface of the resistance spool,

This mechanism comprises a pawl 44,

pivotally mounted at 45, in such a manner that as'the lug 46, carried by the arm 40, reaches its 'maximum upward movement, said pawl will be tripped so as to engage with the ratchet teeth 47, formed on the upper end of the spool 24, andthus impart a slight rotative movement to said spool. Any suitable means may be provided to'pre' vent the operation of said spool 24 in a direction other than that in which the pawl 44 tends to move the same.

It will of course be understood that as the contact arm 40 again assumes its normal position, the pawl mechanism 44 will be returned to its normal position, and will therefore be ready to again be actuated by the contact arm 40, when it again reaches its maximum upward" movement.

While the form of mechanism. herein shown and described, constitutes a preferred form of embodiment of the invention it is to be understood that other forms might be adopted, all coming within -the scope of the claims which follow.

What we claim is as follows:

1. In a rheostat, the combination with a movable support carrying resistance material; of'a movable contact member; and means actuated by the movement of the contact member for moving the support'whereby to present difierent portions of the resistance material to the action of the contact member.

2. In a rheostat, the combination with a movable support carrying resistance material; of a movable contact member; and means intermittently actuated by the movement of the contact member for moving the support whereby to present different portions of the resistance material to the action of the contact member.

3. In a rheostate, the combination with a rotatable support carrying resistance ma- 10c terial; of a contact member movable over said material; and means actuated by the movement of said contact member intermittent-1y to efiect the rotation of said support whereby to present difierent'portions of the resistance material to the action of the contact member. v

4. In a q'heostat, the combination with a resistance carrier carrying resistance material, saidiresistance carrier being provided with a ratchet; a contact element operable to cut in 0*," out said resistance; a pawl element intermittently operable to cooperate with the said ratchet for changing the po sition of the resistance material, so as to present dilferent surfaces thereof to the contact element. I

5. In a rheostat, the combination of a spool-shaped resistance carrier carrying resistanc'e material and provided with a ratchet; a contact element operable to cut in or out said resistance; a pawl element cooperating with the ratchet and intermittently operated by the contact element to change the position of the resistance, so as to present dillerent surfaces thereof to the contact element.

6. In a rheostat, the combination with a ,rotatably mounted cylindrical resistance car- .rier; carrying a spirally wound'l'esistance wire; of a ratchet provided upon said cartures in the presence of two subscribing witrier; a plvotally mounted lever carrying a nesses.

pawl; and a movable member carrying a CHARLES F. KETTERING; contact and provided with :1 lug for engaging WILLIAlVI A. CHRYST.

5 said lever upon a predetermined movement Witnesses: of the movable member in a certain direction. J. W. MCDONALD,

In testimony whereof We aifix our signa- O. D. MOWRY. 

